Mold for casting metals



Oct. 14, 1947" c, yv ss 2,429,145

-MOLD FOR 'CASTINGMETALS 7 Filed Dec. 26, 1942 5 Sheets-Sheet 1 a Carlzdessez 77pgaa J Oct. 14, 1947. c. WESSEL MOLD FOR CASTING METALS FiledD80. 26, 1942 5 Sheets-Sheet 2 Oct. 14 1947. c. WESSEL MOLD FOR CASTINGMETALS Filed Dec. 26, 1942 5 Sheets-Sheet 3 Qt! ll eagel I w? mV C.WESSEL MOLD FOR CASTING METALS Oct. 14, 1947.

Filed Dec. 26, 1942 5 Sheets-Sheet 5 .J L M Z M? Another object I...ofan improved zx zdrawn tubular methods of the prior art.

Patented Oct. 14, 19.47

2,429,145 MOLDFOR casrmc METALS Carl Wessel, Chicago, Ill

Lew W. Cleminson,

assignor to himself and Chicago, 111., as trustees Application December26. 1942, Serial No. 470,167 4 Claims. (Cl. 22-145) The presentinvention relates to an improved method for making thin metal sheets orthin plates. and is particularly concerned with the provision of amethod by means of which such metal sheets or plates may be formed ofhomogeneous large-grained structure without segregated impurities andwith a minimum amount of impurities of any kind.

The present application is a continuation-inpart of my prior applicationwhich resulted in U. S. Patent No. 2,333,286, issued November 2, 1943,and application Serial No..370,344, flied December 16, 1940, for Methodand apparatus for making drawn metal tubes and metal castings, whichresulted in U. S. Patent No. 2,309,608, issued January 26, 1943.

One of the objects of vision of an improved the invention is thepromethod of casting and means of which plates or made which have ahomogeneous large-grained structure andwhich are ing to the prior artmay be eliminated.

of the invention is the provisionand simpler method of making Anotherobject of the invention is the provision of an improved method ofcasting by means of which the defects of the prior art methods, such asblow-holes. inclusions, segregations, faults, cracks, and other defects,are practically eliminated.

Another object of the of an-improved casting method which is adaptableto use in small or large plants and which is adapted to produce metallicmembers having the characteristics of high degree of uniformity of cleanscrap or any other invention is the provision .and by means of whichcrystalline structure and a uniform smooth outer surface adapted to bepolished without necessity for smoothing the surface after casting andbefore the polishing.

Another object of the invention is the provision of an improved methodof casting by means of which tubular structures may be made having ahigh degree of uniformity of crystalline structure they may beconstructed at a minimum cost.

Another object of the invention is the provision of an improved methodof producing a superior cast metal product or a sheet metal productwhich is simple and which involves a minimum number of operations andthe apparatus of which may be made very simple so that a minimumamountof capitaland labor is required in the production of the articlesmade by the process.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings, in which similarcharacters of reference indicate similar parts throughout the severalviews.

. The drawi m ladle;

Fig. 4 is a horizontal sectional view taken on the plane of the line 46of Fig. 3, looking in the direction of the arrows;

Fig. 5 is-a view similar to Fig. 3, with the parts of the apparatus inthe position which they assume during the casting of a thin metal plate;

Fig. 6 is a fragmentary top plan view of the ladle and its cover, withthe mold removed;

Fig. 7 is a diagrammatic sectional view taken on the plane of the line7-1, looking in the direction of the arrows, of Fig. 6, with the moldshown in dotted lines, showing its position relative to the ladle; a

Fig. 8 is a diagrammatic vertical sectional view, taken on a planepassing through the axis of the ladle at right angles to the plane ofthe casting, showing the ladle and mold in vertical position. before thecasting operation;

Fig. 9 is a similar view, with the ladle and mold tilted to such a.point that theflame of the burner is cut off from the mouth of the mold.as takes place in the beginning of the casting operation;

Fig. 10 is a similar view, with the mold and ladle tilted still fartheruntil the free surface of the metal has begun to well up into the mold;

Fig. 11 is a similar view, showing the ladle and mold in a furthertilted position, with the free surface of the metal more than half wayup into the mold;

Fig. 12 is a similar view, showing the ladle and mold tilted stillfurther until the free surface has welled up to the very top of the moldand the mold is full;

Fig. 13 is a similar view, showing the final position to which the ladleand mold are usually tilted, with the mold substantially horizontal andall parts of the mold located substantially below the main body of themetal in the ladle.

In order to illustrate the preferred means for carrying out the method,one form of apparatus or casting machine capable of practicing themethod is now described in detail.

Referring to Figures 1 and 2, the casting apparatus which has beenselected to illustrate the invention, preferably includes a movablysupported ladle indicated in its entirety by the numeral l0, and a moldll directly connected to the ladle l and adapted to be moved with it.The ladle I0 is preferably movably mounted on a pair of bearing framemembers [2, I3 and is preferably so balanced with respect to theassembly ofthe mold H and ladle 10, that it will be normally held inupright position as shown in Figures 1 and 2, even when the supply ofmolten metal in the ladle has been exhausted.

The bearing brackets l2 and I3 may be identical in shape andconstruction and therefore only one of them need be described in detail.These brackets are preferably of suflicient length to permit a maximumdegree of pivotal movement of the ladle and mold and may, in someembodiments of the invention, permit full rotation of the mold and ladlethroughout 360. This may be accomplished by providing a pit in the fioorl4 between the frame members i2 and I3 and extending forwardly andrearwardly of them, or the frame members l2 and I3 may be supported inelevated position upon blocks I5 as shown in Figure 5. 7

Each frame member preferably has a. pair of upwardly extending columnsl6, l1, integrally supported by a bottom frame member l8 which has apair of attaching flanges i9, 20, provided with apertures for receivingthe bolts or lag screws 2|. substantially T-shaped in cross-section andat the upper end of the bearing brackets 12 and I3 they are formedv withthe rectangular opening 22 defined by the frame portions 23-26.

The frame portions 23-26 are preferably provided with threaded aperturesfor receiving the screw bolts 2l--32. Each screw bolt 21 has its innerend engaged in a socket 33 in one of the bearing blocks 34, 35, and thescrews are held in fixed position by lock nuts 36.

The bearing blocks 34, 35 comprise a pair of metal members which, whenassembled as shown in'Figure 2, have plane rectangular sides and areformed with a bearing aperture 31. Since the bearing blocks 34, 35 areadjustably supported by the screw bolts 21-32, they may be brought intoalignment even after the frame members 12 and 13 have been secured inplace, provided the frame members are also substantially in alignment.

30 portion of its outer The frame members iii-48 may be The ladle It maycomprise a substantially cylindrical metal shell, such as the shell 38,having the cylindrical side walls 39 and flat bottom 40. This metalshell may be lined with a layer of suitable insulating material, such asasbestos 4|, covering the inner surface. of its side walls 33 and itsbottom 40.

The asbestos lining 4| supports a second rigid lining 42 of arefractory-material, such as a ceramic product adapted to withstand themelting temperatures to which the metal is to be subiected. This ceramiclining 42 is provided with an inner chamber 43 which may besubstantially cylindrical in shape except that the lower cor- 5 ners arerounded at 44, 45 and the left-hand wall 45 (Figure 3) may be tapered ormay be made substantially frusto-conical at its lower .portionleading toa substantially frusto-conical cover opening 41 at the top.

The opening 41 for the cover plug 48 diverges from the cylindrical shapeat the left-side where it may be provided with a flat wall surface at 43for cooperating with the cover plug 48 to form the walls of arectangular aperture 50 in the top of the ladle Ill.

The cover plug 48 may comprise a frustoconical member of refractorymaterial, such as the same ceramic 42 which is formed to fit in thefrusto-conical opening 41 over the major frusto-conical surface 5|. Atthe right-hand side, the cover plug 48 is formed with a groove 52 whichis half-circular at the upper end and which increases in sizefrustoconically toward the bottom of the plug. When the plug 48 isassembled with the ladle ID, the

aperture 52 at the right-hand side is adapted to provide an upwardlytapered conduit for receiving the burner flame 53 which may be directeddownwardly into the ladle from the gas burner 54 to apply heat to thesurface .of the metal and to be reflected upwardly into the mold H.

At its left side (Figure 4) the cover plug 43 is formed with a groove 50which is rectangular in cross-section and which at its upper end forms adischarge opening 55 of the same size as the filling opening of the moldH to which it is directly connected. The rectangular groove 54 in thecover plug 48 may increase in depth and width toward the bottom of theplug 48 (Figure 3) so as to provide a tapered conduit 56 in this side ofthe ladle leading from the chamber 43 to a discharge aperture which iscoin cident with the filling aperture of the mold.

55 The shell 38 of the ladle ill is preferably supported in abasket-like metal frame which may consist of a metal hoop 51, and aplurality of longitudinally extending metal straps 58--6l which haveinwardly turned ends 62 at their lower end for attachment to the bottomof the shell 38. A transversely extending bar 63 is carried by thebottom of the shell 38 and is adapted to be engaged by a latching lever64 which is pivotally mounted by means of a bolt 65 on one of 5 the legsll of the frame member l3.

The latching bar 34 has a slot 66 which engages the bar 63 when theladle is in vertical position as shown in Figure 2, to retain it in thisposition against any possibility of moving or tipping. A

tension coil spring 61 has one end secured to the frame member 13 at thebolt 30 and the other end pivotally secured to the latching lever 64 bymeans of a block 88 secured to the end of the spring and pivotallymounted by means of the pivot pin 69. The latching lever is thus urgedupper ends and secured by 2 but may be moved out of engagement with itskeeper 88 by pressing downward on the latching lever 84 with the foe IThe hoop I! is secured to the vertical frame members 88'8| at theirintersection by suitable bolts or by welding, and the vertical framemembers 88-8I may be turned outwardly at their means of bolts to a coverplate I8 which may project beyond the outer wall of the shell 88sufilciently to engage the laterally turned ends II of the frame mem-:bers 58-8 I. The cover plate I8 is provided with a rectangular aperture12 located to register with the discharge aperture 88 in the ladle l8and plu 48 and the conduit extending through the cover plate I8 is madecontinuous and smooth-from the conduit 58 into the filling opening ofthe mold II, the aperture I2 being of the same size as the fillingopening of the mold I I. I

The cover plate 18 holds the Plug 48 firmly in place and it is alsoprovided with an aperture I8 (Figure for passing the gas burner nozzle54. The bolts I4 which secure the frame members 58-6I to the cover plate18 may also be used to secure to the top of the cover plate a pluralityof metal bars f|5-I8. of rectangular section and they are a. part of thestructure utilized with other bars for securing the mold directly to thetop of the ladle.

For example, the metal bar 18 may be secured to the cover plate 18 by aplurality of bolts passing through the bar and threaded into the coverplate and the bar I6 is preferably located with its inner face 88substantially parallel to both of the edges of the discharge aperture 12as it is intended to hold one-half of the mold II in proper position inregistry with the aperture I2 at itslower end. 1

. 4 The mold comprises a pair of parts 8| 82 and the lower and leftcorner 83 of the mold half 8| engages the face 88 of the bar lb. Thebars I8 and 11 carried by the .cover plate 18 are preferably elongatedand extend forwardly from the ladle I8 ,over a length which issufllcient to support the half mold member 8| when it is in the positionof Figure 2. For this purpose, the bar members 16 and ll may be bracedby having an upwardly extending frame member 88 at the end of each barmember 7-8, ll, the upper end of which is secured to anotherhorizontally extending bar 85 by means of screw. bolts 88. The barmembers 16, Il may be secured together at regularly spaced points bytransversely extending bars 81, 88, 88 and the inner ends of the bars85may be secured to the fixed mold member 82 by a rivet or bolt 83.

The bars I6, 1'! and the bars 85 are spaced from each other laterallysufiiciently so that the mold member 8| may lie between them and thevertical frame members 84 project above the bars 88 to provide a stopsurface 88 for engagement with the laterally projecting pipe 8| carriedby mold member 8!. Thus, the mold member 8| is prevented from slidingendwise toward the left oif the supporting frame which comprises thebars 18, TI, 85, 84 and others.

The horizontal supporting frame for the mold member 8| may be indicatedin its entirety by the numeral 82. The mold member 82 is preferablyfixedly supported on the ladle I8 by means of a vertically extendingframe on each side. This frame may consist of the vertically extendingframe members 8388 (Figured) which are These metal bars may be on thecover plate 18.

The bars 88, 84 are secured together at regularly spaced points and thebars 85, 88 are secured together at regularly spaced points by means ofscrew bolts and horizontal frame members 88-|8I The frames at togetherby the transversely extending frame member I82.

The uppermost transverse frame members 88 (Fig. 3) are joined by a framemember I83 which may have a beveled surface I84 on the side whichengages the fixed mold member 82. The fixed mold member is preferablysubstantially rectanular in elevation and comprises a metal memberprovided with a plane, smooth and polished surface I88 forming one ofthe sides of the mold cavity I88.

The two mold members 8| and 82 are made of metal having a higher meltingpoint than the metal which is to be cast into plates. For example, whencasting aluminum and certain other alloys. cast steel molds may be used.The mold member 82 is preferably provided with a rearwardly extendingreenforcing border flange I81 extending on all the four edges of thebody plate I88 and it is also preferably provided with a plu- I88.Vertically extending reenforcing ribs may also be employed for thepurpose of preventing the warping of the mold, and the lower edge of thefixed mold so that it will fit against the cover plate 18 when the moldis disposed at an angle as shown.

The face I85 of this mold 82 registers with the opening I2 in the coverplate I8 which in turn registers with the discharge opening 55 from thechamber 43 of the ladle. The width of the mold members 8|, 82 is suchthat the mold cavity I 88 0 is as wide as-the discharge openings 12 and58 are long. The thickness of the mold cavity I 86 is the same from topto bottom and is of such thickness that the lower open end of the moldhas the walls of its cavity in registry with the edges of the opening 12in the cover plate I0.

- The fixed mold 82 rests againstthe frame mem ber I83 at the top andagainst the cover plate 18 at the bottom and is preferably secured inplace by a plurality of screw bolts II| extending through the framemembers 89 and threaded into the flange of screw bolts II2 (Fig. 7) maypass through the lateral frame-members l1 and may be threaded into theflange I81 (Fig. 5) of the mold 82 ad- Jacent its lower end.

The movable mold member 8| preferably has a body portion which issimilar in construction, body plate H3, a

ever, is preferably provided which extends across the top of the moldmember 8| and down both sides of the mold member 8|, but is open at thebottom, thereby defining a mold filling opening I. This mold member hasits lower border fiange H8 provided with an oppositely beveled surface 8so that it may fit against the cover surface H8 is such that when thetoe 88 of the mold 8| engages the bar the filling opening Ill is inregistry with the opening I2 in the cover plate 18. Thus, the mold II isadapted to have a filling opening which is of substantially the 75 samesize as the discharge opening in the ladle,

82 is preferably beveled as at IIIl plate 18. The width of this securedto the horizontally extending bars 81, 88

each side are secured rality of transversely extending reenforcing ribsI81 of the mold 82. Another pair the reasons for which will be describedhereinafter.

The movable mold 8i may be provided with a handle III which is ofsufficient length to pro- :Iect laterally from may comprise a metal pipewhich is secured to the vertically extending reenforcing flanges II4(Fig. 1) by a plurality of screw bolts I20 which pass through aperturesof the pipe and are threaded into the flanges I I4. The handle alsoserves the purpose of providing a support for the mold 8| when it ismoved into the dotted line position of Fig. 2, resting on the framemembers by means of handle 9|.

The fixed mold 02 is preferably provided with means for holding themovable mold Si in tight engagement with it as follows: At the upper endof the fixed mold 02, there is secured to its rear side on each of thereenforcing ribs II4, an upwardly extending metal bar I13. Each of thesebars and its assembled parts are identical so that only one need bedescribed. Each bar H3 is secured by means of screw bolts I2I passingthrough the bar and threaded in ribs I I4 of mold member 02. At itsupper end the bar IIS pivotally supports a lever I22 by means of screwbolt I23. Lever I22 carries a pivoted wedging member I24 by means ofscrew bolt I25. Wedging lever I24 has its lower inner end beveled at I20and the lever I22 may have a fiber extension I21 for grasp by the handsof the operator.

The upper flange I01 of the fixed mold 02 also supports a. pair offorwardly extending keeper frame members I28 spaced from it by a spacerI29. Keeper frame members I28 are joined by a keeper bar I30 which maybe secured thereto y The operation of the securing means is as follows:

The wedging lever I24 engages the rib II4 of movable mold member 0|.When the lever I22 is pulled downward by its handle I21, its outer sideengages the bar I30 and its beveled surface I26 engages the mold. Theproportions of the parts are such that wedging lever I24 is driven inbetween the mold 8| and bar I30 as a wedge to hold the mold members 01and 02 together. The wedging action thus provided is sufllcient to holdthe two halves of the mold tightly together, but it is also adapted totake care of the expansion of the mold when the hot metal is poured intothe mold.

The supporting framework for the ladle I0 also includes a pair ofupwardly extending frame members I3I, I32, secured by means of screwbolts to the ladle shell 38 at the bottom and to the band 51. The framemembers I3I, I32, preferably extend upward beyond the cover plate wherethey may be bent outwardly slightly as indicated at I33, I34. andprovided with the horizontal handle portions I35, I36.

Thus, the ladle and mold assembly has a handle I35, I35 at each endwhich may be grasped by a pair of operators or either of them in tiltingthe ladle and mold from the position of Fig. 3 to Fig. 5.

The mold II is also preferably provided with a pair of.similar wedgingmembers, one located at each side of the mold. In this case, the fixedmold is provided with a pair of forwardly extending strap members I31,I30, joined by a transverse strap I39 to form a keeper similar to I20,I20, I30, previously described.

A pivoted lever I40 comprising a pair of straps I4 I, I42 spaced andsecured to a handlebar I43 both sides of the mold II. It 1 welding orany convenient fastening means.

is pivotally mounted on a f-rame'member; I44 by means of a screw boltI45. A similar wedging member I45 extends between the straps I31, I30and inside the strap I39 to engage the mold BI and this wedging memberI40 is pivotally mounted on lever I40 by screw bolt I41. A

The frame member I44 may be a fixed member carried by the verticallyextending bars 06. In this case the action of the wedging members is thesame as described with respect to the wedging members I24 at the top,there being sufficient space between the mold to permit the necessarypivotal movement of the levers I40.

The interior of the mold cavity I00 in the mold member 8i likewise hasits surface I40 in a substantially plane, smooth and polished condition,and the same is true of the inner surface I49 of the border flanges H5at the end and both sides. Thus, the mold cavity I06 is of uniformcrosssection from top to bottom and of uniform size.

The angular tilt of the mold cavity I06 with respect to the top of theladle I0 is preferably such that when the ladle and mold are tilted, thefree surface I50 of the molten metal I5! is adapted to well upward intothe mold as the tilting progresses. The metal does not, therefore, rundown to the end I49 0f the mold cavity I00, but it moves upward into thecavity in a solid stream of uniform cross-section until the cavity isentirely filled and thereafter the continued tilting of the mold to theposition of Fig. 5 permits a pressure to be placed on the metal in themold which is determined by the head of metal above the mold cavity inthe ladle in Fig. 5.

The cover plate I0 may be provided with a sliding cover I52 slidablymounted in guides I53 and provided with a slot I54 for engaging the gasburner pipe. The cover plate I52 may be provided with a handle I55 sothat it may he slid to the open or the closed position by means of thehandle. Thus, the burner opening may be closed, if desired, or, ifnecessary, to prevent the spilling of the metal out of the burneropening when the mold is tilted to the position of Fig. 5.

The method and operation of the apparatus is as follows: The ladle I0 ispreferably preheated by means of the gas burner 54, the flame 53 ofwhich plays into the cavity 43. Metal may be melted in one or moreseparate furnaces and a suitable supply of clean molten metal such asthat provided by clean scrap or by ingots, may be placed in the cavity43 after which the cover plug 48 and cover plate 10 may be secured inplace. The burner 54 is then again directed into the ladle cavity 43 andthe flame is reflected from the free surface I50 of the molten metalinto the mold cavity I06. This drives out the air and maintains aconstant supply of neutral atmosphere, comprising exhaust gases. Thepressure in the ladle is maintained slightly above atmospheric pressureso gas flows out crevices and air or oxygen cannot enter.

The apparatus may be preheated by means of this flame and by casting afew plates to bring it to the proper temperature. Thereafter, thecasting operation may be carried out as follows: The mold having beenclosed and secured by means of 0 the wedges, the ladle and mold aretilted gradually from the position of Fig. 3 in a counterclockwisedirection. As the ladle is tilted, the free surface of the molten metalI5I is, of course, maintained in horizontal position, and as the mold islowered, this free surface rises in the mold the handlebars I33, I34 and"filled. The air or gas between the mold halves by the pressure ofthe vor gas.

. adjacent the walls of cavity I 08 due to the tilted position of themold on the ladle.

The rising continues during the tilting operamold at the bottom andmoves uniformly up throughthe mold until the mold is completely moltenmetal which is'sumcient to expel the air As the tilting is continueddownward to the position of Fig. 5, after the mold has been filled,

a predetermined pressureis placed upon the metal in the mold andwhile-the metal pressure is continued until the pletely taken up by thehead of sure applied to the mold.

The casting in the mold freezes from the flat surfaces of the moldinward toward the center, and ii the mold is tilted backward quicklyenough, a hollow plate may be formed or a hollow tube may be formed bythe metal which has congealed the mold, the molten metal running out ofthe inside to leave the casting hollow. Thus, the present invention maybe used for making hollow castings or hollow tubes of any cross-section.

It should be understood that the cross-section of the mold may becircular for the making of hollow round'pipes or it may be square orhexagonal or triangular or rectangular or any known or desired geometricform, the filling opening of the mold being of the same size and shape.The casting also congeals from the outer end of the mold, that is, theupper end in Fig. 3, toward the filling opening, the lastto congealbeing that portion adjacent the filling opening, so that additionalmetal is supplied to the casting as'it congeals and all shrinkage istaken up.

In order to permit sufficient time for this congealing. the tiltingaction of the mold is so carried out that a predetermined number ofseconds or counts are employed, or the mold may be held-for a short timein the position of Fig. before it is tilted back into the position ofFig. 3.

As soon as the mold is tilted back to the uppermost position the wedgesare released and the movable mold member BI is moved away from the fixedmold 82 and the movable mold is laid upon the horizontal supports 85.The casting will then be lying against the fixed mold member 82 and avery short sprue may extend'into the discharge opening 55 of the ladle,but a minimum amount of sprue is present and there is a minimum amountof metal wasted by sprue action.

The result is a cast metal plate of homogeneous uniform grainedstructure without any segregations of impurities and without any pipe orcavity in the case of a solid casting. The present metal has been foundto have an increased tensile strength and an increased purity over themetals cast according to the methods of the prior art, and the metalsare particularly adapted to be used for drawing out metal cans ortubular containers such as the cans that are used for shields coveringradio tubes of radio receivers.

The superlative product resulting from the use of this apparatus isattributed to the method of casting which may the present or otherapparatus and which is summarized as follows:

The method is preferably carried out by means a, closed insulated ladlehaving a mold directly in the mold cools, shrinkage is commetal. underpresattached to the discharge opening of the ladle so is expelled fromthe crack that there is practicallyno sprue attached to the The mold isof metal of a higher meltished on all sides.

The cross-section of the mold is preferably uniform from one end to theother for the casting of plates or other articles of uniformcross-section, and the filling opening of the mold, which is in registrywith thedischarge opening of the ladle, is of the same size as thecross-section of the mold. The discharge opening from the ladle is Theladle is filled to a clean molten metal,

tained in the ladle to keep air out.

The casting operation is then carried out with the mold in directconnection with the ladle and by tilting the mold until the metal wellsupward into the mold in a solid unbroken stream without any agitation orchurning. The congelation of the metal may begin as it enters the mold,but nevertheless the solid plug of the metal in the ladle. The slidingengagement with the polished sides of the mold has a burnishing actionon the finished casting.

The method of casting preferably includes the application to the mold ofa gaseous flame, which is so adjusted that it produces a certain amountof soot in every fine condition. This may be done by using an excess ofgaseous fuel, suchas illuminating gas, over other words, the gaseousfuel predominates over 5 the oxygen supply which would be required forperfect combustion, flame.

This-soot may uniformly coat the conduit leading from the ladle to themold, and may coat the thereby producing a red 0 metal surfaces of themold with a thin, fine layer of pure carbon. This carbon reduces thesurface tension of the aluminum alloy filling the mold, and causes it tofill the mold more perfectly, but is sufliciently thin and-fine so thatit does not affect the surface of the casting, which conforms quiteexactly to the cavity of the mold and provides a smooth and finishedcasting.

In addition to this, the carbon coating facilitates the separation ofthe mold from the casting, making the removal of the casting from themold, or vice versa, easier than it would otherwise be.

Where the article to be cast is of uniform crosssection, so thatcongelation may start as the metal enters the mold. the carbon coatingacts as a the supply of oxygen. In

lubricant for the entering metal and aids in producing a more finishedsurface.

Before the casting operation is begun, the flame impinges on the freesurface of the metal, and-is reflected into the mold to preheat themold, and

especially to heat the filling aperture.

As the tilting progresses and the free surface covers the fillingopening of the mold, the flame continues to heat the metal in the ladle,and when the mold and ladle have reached their extreme position theflame impinges against the wall of the ladle to continue the supply ofheat for maintenance of the temperature of the molten metal in theladle.

Thus the flame is automatically cut off from the filling aperture of themold by the tilting action, and automatically re-applied to the metalwhen the ladle and mold return to their original position.

The temperature of the metal in the ladle is preferably maintained asclose as possible to the melting temperature of the metal used incasting, that is, slightly above the solidifying temperature, sothat'when cast it solidifies quickly in the mold.

. Less time is thus required for casting, and any tendency towardsegregation is minimized by quicker congelation. The tendency towardsegregaticn is greatest during congelation, and quicker congelationreduces or substantially eliminates segregation of impurities andsegregation of ingre ients of an alloy.

This close to congelation maintained by frequent measurement andconstant observation of the indicated temperature of the molten metal inthe furnace, by adiustment of the furnace and ladle'temperature, byadjusting the heating arrangements of the ladle and of the furnace andby replenishing the ladle supply at proper time and temperature.

The ladle gas burner can. be adjusted to higher or lower heat; or, ifthe metal in the ladle or furnace is too hot, 9. small solid piece ofclean metal can be thrown into the molten metal to absorb heat by reasonof its being heated and melted. The heat of fusion is taken from thesurrounding molten metal, thereby reducing the tem erature o a'l of themetal when molten.

For example, the silicon aluminum alloy 356 of the Aluminum Company ofAmerica has a a composition of 7% the rest aluminum. a range ofsolidificat on of from silicon, 0.3% magnesium, and

1130 degrees F.

to 1075 degrees F. Using this alloy, the molten metal in the furnace maybe maintained at a. temperature not over 1300 degrees F. and not lessthan 1250 degrees F.

Under the same conditions, with small castings of irregular shape, thetemperature of the metal in the ladle may be maintained at from 1175degrees F. to 1200 degrees F.; but, if the machine is used for castingthin plates, the temperature of the molten metal in the ladle may bemaintained at a temperature between 1225 degrees F. and

1250 degrees F.

Under these conditions the mold might be maintained, for example, at atemperature of from 600 degrees F. to 700 degrees F., preferably atabout. 650 degrees F.

It is also found that the proper temperatures for the molten metal inthe ladle decrease during operation from the proper temperature whichshould be used in the beginning. For example, in the beginning, when theladle is bringing the mold and other parts up to proper temperature, one

the ladle and of that in may start with a temperature of 1250 degrees F.with this alloy, and a half hour later reduce the operating temperatureof the metal in the ladle to 1200 degrees F., and still later to 1175degrees F. in the ladle, which may be then used for the substantiallyconstant operating temperature.

The mold being attached directly to the ladle, with only one partdetachable, keeps the mold hotter than it would otherwise be, but themold is maintained at a temperature lower than that of the molten metalin the ladle, as indicated above, in order that it may cool the moltenmetal when the mold has been filled, and effect a quicker congelation.

In order that the mold may be cooler than the ladle parts, it isprovided with some heat insulation between it and the ladle.

temperature is While in some embodiments of the invention artificialcooling by liquid or gas might be used, the temperature differentialbetween the mold and the ladle andbetween the respective parts of themold is preferably so regulated by the construction of the mold andladle that no artificial cooling is needed for most castings.

In the apparatus illustrated the amount of metal used in the mold andthe proportions of the mold and the amount of heat radiating surfaceprovided are adapted to effects. proper cooling without necessity forartificial means, and these proportions are shown in the drawings.

The tilting is preferably carried out slowly so that the mold is filledslowly, and when the mold is filled the tilting is continued until thefull pressure of the remaining metal in the ladle is placed on the metalin the mold.

Referring to Figs. 8 to 13, these figures show progressively the actionof the flame and the molten metal during the casting operation.

In Fig. 8 the ladle is in upright position, and the.

flame is playing on the free surface of the metal, and is deflected intothe mold.

Assuming that the dross on the surface has been skimmed off, the castingoperation may then gun to well up into the sprue or filling conduit.

This alloy is stated to have as shown in Fig.

As the tilting proceeds, it will be seen in Fig. 10 that the metal wellsup into the mold. In this figure it has just begun to enter the mold.Further tilting causes the free surface of the metal to well up fartherinto the mold.

In Fig. 11 the mold is more than half way full.

In Fig. 12 the tilting has progressed to such a point that the mold isentirely full. This position is such that the free surface of the metalis above every part of the mold cavity.

The tilting is then continued to the position 7 of Fig. 13, in whichsubstantially every part of the mold cavity is below the main body ofmolten metal in the ladle. When a plate is being cast, 13, the moldcavity may be in substantially horizontal positio In this position thepressure 01 the head of metal in the ladle is applied to the metal inthe U mold.

For some embodiments of the invention it is only necessary to proceed tothe position of Fig. 13, but in others the tilting may be continueduntil the mold is substantially or entirely inverted, the mold'being invertical position, with the opening for the burner closed.

There are advantages in this additional step of inverting the mold andcasting after the filling it at of the mold, as the natural h'eatgradient is then established from the lowermost and coldest part of themold to the uppermost and hottest part of the mold near the ladle.

For example, at the temperatures mentioned, varying from 1250 degrees R,beginning, down to a stated temperature of 1175 degrees F., one hundredand twenty casting might be made per hour;

and of course the major part of this time is spent in removing thecasting from the mold and reassembling the mold.

The exact amount of time which should be taken up in tilting the moldand the speed of tilting may be determined best by trial. For example,between five and ten seconds might be used in the timing of the downmovement of the mold; but this may be varied by reason of the followingconditions.

The thinner the cavity, the faster the filling and the freezing shouldbe; and therefore the thinner castings must be made b .tilting at afaster speed. The heavier the casting, the slower the filling may be,and in such case the mold may be brought down slowly, consuming as muchas thirty seconds. The speed of the down movement is important; and ifthe downwardmovement is properly timed, the casting will be well formed.

In some cases, after the down movement has been completed, the mold maybe lifted at once;

but if the castings are heavier, the mold must be held down in the lowerposition for a certain number of seconds, until the congealing isaccomplished inward from both sides of the mold, and back from the endof the mold to the filling aperture.

One advantage of holding the major axis 01' the mold in substantiallyhorizontal position during congelation, or of merely moving it to thesubstantially horizontal position to fill the mold, is that all parts ofthe cavity will be subjected to substantially the same head of pressureby the metal in the ladle, because they are at the same level, and thepressure should be the same in a plane parallel to the free surface andat a predetermined distance below the free surface.

The tilting is preferably carried outslowly so that the mold is filledslowly and when the mold is filled, the tilting is continued until thefull pressure of the remaining metal in the ladle is 5 placed on themetal in the mold.

The metal in the mold then congeals from the large plane fiat surfacesof the mold inward toardthe center and from that end of the mold remotefrom the filling opening back to the filling opening. As the cooling ofthe casting takes tion and full metal pressure applied for a short timeuntil congelation takes place. The timing depends upon the metals whichare being cast and upon the characteristics and thickness of the moldand the temperatures employed.

When hollow castings, such as tubes or hollow lates, are to be made, theladle and mold are tilted backward to the uppermost position immediatelywithout any delay and the thickness depends upon the temperatures andthe speed of tilting and re-tilting. This may quickly be determined bytrial, and it is not possible to specify any given time except with agiven apparatusat a given temperature. L

There is no spurting otthe metal out of a nozzle into the 'mold, noforming of drops or separate oxidised particles, and the only part ofthe casting which is subjected to air is that small area at the end orthe solid advancing stream or metal in the mold and that end portionbecomes the end oi the casting.

The present method may be used for casting various types of metals andalloys, and it is only necessary to use suitable molds of metal of amelting point higher than the metal to be used in casting. I

As soon as theassemblyis tilted back to the upper position, the wedgesare released and the movable mold members withdrawn and the castcoolinginfluences.

When the metal is to be used for drawing metal I containers, the platesmay be taken to a punching prior art.

It an improved method of making castings and grained homogeneousstructure without any segregated impurities or cavities or otherdefects.

As the mold opening is of the same size as the ladle discharge opening,the metal may well up into the mold without any agitation or spurting orsplashing, and there are no small particles or, drops formed which mayharden first and be oxidizedon their outside and then incorporated 65 inthe casting. The casting comprises one uni-' 70 gauge and width, but theamount of rolling that is necessary is very small because of the initialthin character of the plate castings. amount of rolling is eliminated,and the cost of the metal sheets is greatly reduced.

75 According to my method, no part of the melted the invention,

- cavity and also metal is ever separated from the compact stream ofmelted metal walling up into the mold. If any part of the metal becomesseparated from the stream, it wouldbe surrounded with oxygen and becomeoxidized, and would not fuse again in the mold to make such ahomogeneous structure as I am able to secure.

While I have illustrated a preferred embodiment of my invention, manymodifications may be made without departing from the spirit of and I donot wish to be limited to the precise details of constructionset forth,but desire to avail myself of the scope of the appended claims.

Having thus describedmmy invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

all changes within 1. A permanent mold assembly comprising a metal platehaving a mold filling opening therein, a pair of longitudinallyextending metal frame members carried by said plate, and a pair oftransversely extending frame members projecting transversely from saidplate and secured to said longitudinal frame members, a mold membercomprising two halves, one of said halves fitting between saidlongitudinally extending frame members adjacent said filling opening andhaving its inner surface in registry with the edge of said fillingopening, said transversely extending frame members having a cross headadapted to support said one half of the mold, the second half of saidmold member being provided with a cavity and also fitting betweensaid'longittudinal and transverse frame members against the first halfof the mold, said cavity being formed with an opening at its lower endin registry with said filling opening in said plate, and means forsecuring said mold halves together, said latter means comprising apivoted lever carried by the first mold half, and a cross bar carried bysaid first mold half, a wedging member pivoted on said lever, andadapted to be engaged between the cross bar and the second mold half.

metal plate having a mold filling opening therein,

a pair of longitudinally extending metal frame members carried by saidplate, and a pair of transversely extending frame members projectingtransversely from said plate and secured to said longitudinal framemembers, a mold member comprising two halves, one of said halves fittinbetween .said longitudinally extending frame members adjacent saidfilling opening and having its inner surface in registry. with the edgeof said filling opening, said transversely extending frame membershaving a cross-head adapted to support said one half of the mold, thesecond half of said mold member being provided with a cavity and alsofitting between said longitudinal and transverse frame members againstthe first half of the mold, said cavity being formed with an opening atits lower end in registry with said filling opening in said plate, andmeans for securing said mold halves together, said plate also havinglongitudinally extending frame members pro- 2. A permanent mold assemblycomprising a metal platehaving a mold filling opening therein, a pair oflongitudinally extending metal frame members carried by said plate, anda pair of transversely extending frame members projecting transverselyfrom said plate and secured to said longitudinal frame members, a moldmembercomprising two halves, one of said halves fitting between saidlongitudinally extending frame members adjacent said filling opening andhaving its inner surface in registry with the edge of said fillingopening, said transversely extending frame members having a cross headadapted to support said one half of the mold, the second half of saidmold member being provided with a fitting between said longitudinal andtransverse frame members against the first half of the mold, said cavitybeing formed with an opening at its lower end in registry with saidfilling opening in said plate, and means for securing said mold halvestogether, said plate also having a transverse shoulder member secured onthe plate to engage the outer surface of the second half of the mold tohold the parts of the mold together at said plate.

3. A permanent mold assembly comprising a vided with a cross-bar and ofsufllcient length to support the second half of the mold when it hasbeen separated from the first half.

4. A permanent mold assembly comprising a metal plate having a moldfilling opening therein, a pair of longitudinally extending metal framemembers carried by said plate, and a pair of transversely extendingframe members projecting transversely from said plate and secured tosaid longitudinal frame members, a mold member comprising two halves,one of said halves fittin between said longitudinally extending framemembers adjacent said filling opening and having its inner surface inregistry with the edge of said filling opening, said transverselyextending frame members having a cross-head adapted to support said onehalf of the mold, the second half of said mold member being providedwith a cavity and also fitting between said longitudinal and transverseframe members against the first half of the versely and longitudinallyextending spaced rein forcing ribs.

CARL WESSEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,333,286 Wessel Nov. 2, 1943440,801 Adams Nov. 18, 1890 r 954,368 Allison Apr. 5, 1910 1,533,734Gotze Apr. '14, 1925 2,106,614 Lindner Jan. 25, 1938 94,170 Pedder Aug.31, 1869 1,138,443 Bie'rbaum May 4, 1915 1,368,445 Little Feb. 15, 192148,215 Sexton June 13, 1865 905,287 Chipman Dec. 1, 1908, 2,134,829McWane Nov, 1, 1938 2,223,617 Johnston Dec. 3, 1940 2,209,519 HalbrockJuly 30, 1940

